Search

The PVSDM model was used for single and binary dye adsorption systems. This model is commonly used for adsorption in single systems, but this is the first time used in a binary mixture of dyes in the literature. To that end, a new adsorbent derived from Bauhinia forficata waste was created and described for eventual use in the treatment of a dye combination (methylene blue and crystal violet). The single and binary isotherms revealed that increasing the temperature decreases the methylene blue adsorption capacity while increasing the crystal violet adsorption capacity. The Langmuir and extended Langmuir models described the single and binary systems, respectively. Maximum adsorption capacities of 229.13 mg g−1 at 298 K for methylene blue and 324.12 mg g−1 at 328 K for crystal violet were obtained. The thermodynamic parameters showed that the adsorption process for both dyes is spontaneous, being exothermic for the methylene blue and endothermic for the crystal violet. Similar decay curves for the single and binary systems were observed. The PVSDM was able to describe both single and binary adsorption systems. The external mass transfer and the surface diffusion change according to the initial dye concentration and the system type (single or binary).

In this work, buckwheat husks (Fagopyrum esculentum) were modified by acid treatment and posteriorly employed to remove the ketoprofen in batch adsorption. The characterization results indicated that a more irregular surface with new empty spaces was generated after acid treatment. The adsorptive process was favored at acidic pH = 3. The dosage of 0.85 g L−1 was fixed for the kinetic and isothermal tests, obtaining good removal and capacity indications. The kinetic studies were better represented by pseudo-second-order, obtaining an experimental capacity of 74.3 mg g−1 for 200 mg L−1 of ketoprofen. An increase in temperature negatively affected the adsorption isotherm curves, resulting in a maximum capacity of 194.1 mg g−1. Thermodynamic results confirmed the exothermic nature of the process with physical forces acting. The adsorbent presented high efficiency in treating a synthetic effluent containing different drugs and salts, 71.2%. Therefore, adsorbent development from buckwheat husks treated with a strong acid is an excellent alternative, given the good removal results and the low cost for its preparation.

The residual bark of the tree species

In this work, buckwheat husks (Fagopyrum esculentum) were modified by acid treatment and posteriorly employed to remove the ketoprofen in batch adsorption. The characterization results indicated that a more irregular surface with new empty spaces was generated after acid treatment. The adsorptive process was favored at acidic pH = 3. The dosage of 0.85 g L

A series of geopolymers were synthesized from fly and bottom ashes of a thermoelectrical power plant located in the Brazilian southern, aiming to add value for these wastes. The geopolymers were prepared in conventional and ultrasound-assisted ways and used to uptake Ag

This study used the bark of the forest species Campomanesia guazumifolia modified with H

Real hospital wastewater was effectively treated by a promising technology based on degradation reaction catalyzed by Fe

In this work, comminuted seedpods of the forest species Luehea divaricata (LDPR) and Inga laurina (ILPR) were used as alternative and environmental-friendly adsorbents for the methylene blue (MB) removal from aqueous solutions. Batch adsorption experiments were carried out at the native pH of the solution (pH = 8.7), with curves of removal and adsorption capacity crossed at 0.75 g L

To evaluate the influence of new air-abrasion powders with different silica concentrations (silica-coated aluminum oxide) and aging on the bond strength between composite cement and Y-TZP ceramic.Ceramic slices (7 x 6.3 x 2 mm3) were randomly allocated into 8 groups (n = 20) considering different surface treatments (SiC: silica-coated aluminum oxide particles; AlOx: aluminum oxide particles; 7% Si and 20% Si: experimental powders consisting of 7% and 20% silica-coated of AlOx respectively) and aging (baseline: 24 h at 37°C in water; aged: 90 days at 37°C in water + 12,000 thermal cycles). A blinded researcher performed the air-abrasion procedure for 10 s (identical parameters for all groups). Composite resin cylinders (Ø = 3 mm) were cemented onto the silanized ceramic surfaces, light cured, and subjected to shear bond-strength testing (wire loop Ø = 0.5 mm). The topography of the powders and air-abraded surfaces was analyzed using SEM and atomic force microscopy (AFM). The elemental composition of the powders and air-abraded surfaces was analyzed with energy dispersive spectroscopy (EDS), and surface wetting of the air-abraded surfaces was also determined by contact-angle measurements.Under baseline conditions, all groups presented similar bond strengths, but only SiC and 7% Si yielded unaltered bond strength after aging. SiC and 7% Si presented lower contact angles. All groups presented similar surface topographies. The silica content was also similar among groups, except for AlOx.7% Si and SiC presented similar bond strength and better bonding performance after aging than AlOx and 20% Si. A higher silica concentration was not able to promote stable adhesion of composite cement after aging.

A novel CoFe

An easy preparation of magnetic particles with a chitosan external layer and zinc ferrite as core material was proposed. ZnFe

An alternative activated biochar was developed from barley malt bagasse (BMB) through pyrolysis followed by CO